Geological Time-Scales

In the geology/paleontology community, the scheme in general use is more complex. For example, from the Hadean through the Proterozoic constitutes the "Precambrian" time-frame; from the Cambrian through the Permian constitutes the "Paleozoic Era"; from the Paleocene through the Pliocene constitutes the "Tertiary sub-Era"; from the Paleocene through the Holocene constitutes the "Cenozoic Era". The continuous time-scale presented above is a simplification, but any wider time-frame in use can be conveniently represented by a doublet from the above time-scale. The so-called "Quaternary" sub-Era, for example, is the time- frame Pleistocene-Holocene inclusive.